Giving a choice, to a persistent coach, that can be effective either way, calmly & privately as possible, "Coach, YOU have a choice. YOU can choose to keep your comments, to me or my crewmates, civil & appropriate and remain on your sideline to coach your team however you decide, or you can say whatever you want, as loud as you choose, to whomever wants to listen to you, in the parking lot." You don't have to wait for an actual/specific selection.